Review for Celestron NexStar 130 SLT Series Newtonian Reflector Telescope - 31145

Author: Senske {!} from Spokane, WA on Jan 10, 2009
Pros:  Easy to Setup and Use. Finderscope is Great
Cons:  Bad Mirror, SkyAlign Fails Often
Would recommend:  no

Senske wrote:

I have really mixed feelings about this telescope. For the most part it works as expected, but after the first night of viewing in cold weather (about 10F) the mirror coating has started to deteriorate, causing what appears to be significant bubbling or pitting around the entire perimeter of the mirror and less significant imperfections across the surface of the mirror. This is my first telescope, so I'm no pro, but I'm guessing this mirror failure is due to the expanding and contracting of the relatively low-quality mirror. If you're looking for an excuse to buy a really high-quality telescope with zero-expansion optics just keep this in mind. The hand control display doesn't work well in cold weather, either. The scrolling text on the LCD screen is unreadable and response to input is slow. At 35F - 40F this isn't an issue. Battery life at 10F was about 2 hours. SkyAlign worked the first time (thank goodness for that), but hasn't worked since. I've switched to using Solar System Align with my exact GPS coordinates. This is much easier and less time consuming than using SkyAlign, and the result is fairly accurate alignment. If you're new to astronomy like me, you certainly won't be blown away by this telescope. Saturn looks like a tiny little star with a line through it when using a 9mm eyepiece and 2x barlow lens. That's about 144x magnification. I haven't tried my 4mm eyepiece but that would more than double the magnification to 325x which might make Saturn look more like Saturn. Note that the manual says the highest useful magnification is 306x. If the mirror wasn't defective, I'd keep this telescope for sure. Now I'm thinking of exchanging it for the same telescope to see if my mirror problem was a fluke, or checking to see if Celestron will simply send me a new mirror to install. Overall, a bummer of an experience with a first telescope because of the mirror. I hope all telescopes aren't like this.